Mechanical ventilation is a commonly accepted medical practice for the treatment of individuals experiencing respiratory problems. These patients may not be spontaneously breathing at all, such as a patient that may be in an intensive care unit. In these instances, mechanical ventilation is provided according to a clinician defined respiratory therapy trajectory. Alternatively, the patient may be too weak from disease and/or sedated from an anesthetic agent to complete an entire respiratory cycle under his own power. In these instances, mechanical ventilatory assistance is provided whereby patient spontaneous breath attempts are detected by the ventilator using transducers placed in the ventilator breathing circuit to detect when the patient spontaneously attempts to breathe.
A respiratory therapy trajectory describes a ventilator delivery to achieve a desired ventilatory result and can be defined by a time varying-pathway or a combination of the necessary vent settings. For example, the time-varying pathway can be the inspiratory flow or airway pressure patterns of the ventilator. Examples of the vent settings include but are not limited to: tidal volume, respiration rate, inspired and expired duration, inspiratory and positive end-expiratory pressures that are common to ventilator settings, pressure overshoots, and rise times. The respiratory therapy trajectory determines the delivery of the ventilation therapy. The respiratory therapy trajectory is to be distinguished from the measured respiratory therapy waveform, as the respiratory therapy waveform is the measured effect of the ventilation therapy set according to the selected delivery trajectory. In general operation a clinician will create a trajectory, the respiratory therapy will be delivered according to the trajectory and a sensor will measure the resulting waveform.
A patient receiving mechanical ventilation may also receive therapeutic treatment from the way in which the mechanical ventilator delivers the respiratory therapy. Modification of various parameters of the mechanical ventilator can help to improve patient respiratory function. These modifications may include modifications to the respiratory therapy trajectory of medical gas that is delivered to the patient for each patient breath, modifications to the various patterns of changing ventilatory pressures, the addition of supplemental medical gases to the requisite air for the ventilation, and the length and/or combination of any of these and other treatment modifications. Specifically, modifying the pressure at which medical gas is delivered until the ventilator cycles to an expiratory phase can help improve patient lung function. In this form of treatment, different patterns of changing ventilatory pressure can produce different results and as such the clinician must tailor a respiratory therapy trajectory to a patient to ensure that the patient receives the proper treatment.
There are several limitations, however, associated with current ventilatory systems and the means by which the respiratory therapy trajectories may be modified for the clinician to provide the proper respiratory therapy to the patient. Under currently available ventilatory systems, the clinician must enter the respiratory therapy trajectory data by entering ventilatory parameters in numerical form into the ventilator controls. Additionally, a clinician scrolls through a table to choose the parameter of interest. Upon selecting the parameter the trajectory is displayed. The user can change this parameter through the menu updating the trajectory. Finally, the user confirms the desired setting which also navigates them back to the table of parameters. This approach only allows one parameter to be modified through this sequence of menu operations. This tedious sequence of steps must be repeated to change additional parameters. These processes are difficult for the clinician because it requires pre-computation of many of the ventilatory parameters as well as the management of these ventilatory parameters. Furthermore, the clinician must visualize the trajectory or sketch it on a piece of paper since there is no visual feedback as to the trajectory that the clinician is creating. Additionally, current ventilatory systems do not provide the clinician with feedback comprising the resulting effects that the modification of the ventilatory parameters by the clinician has on other parameters of the ventilatory system. Therefore, the clinician does not know, unless further calculations are performed, the full extent of the effect a parameter selection may have on ventilator function. The creation of a trajectory with tabular data places a greater cognitive load on the clinician as opposed to creating the trajectory graphically.
Furthermore, ventilator systems produced by different companies use different names for respiratory therapy trajectories. This may confuse a clinician who must switch between various ventilator platforms. Alternatively, respiratory therapy trajectories with similar names may function differently across ventilator platforms. These differences make it difficult for clinicians to operate and/or become proficient at the use of multiple brands of ventilators.
Therefore, it is desirable in the field of mechanical ventilator systems for an intuitive interface where a clinician can easily graphically modify a ventilation parameter. Furthermore, it is desirable that upon the entry of a modification to a ventilatory parameter, the clinician be presented with the ventilatory operation consequences of the modification to the parameter. It is also desirable for an improved method for the entry of desired modifications to the therapeutic ventilatory pressure trajectory, such that it is easy to modify the pressure trajectory to individually tailor a ventilatory pressure treatment to the patient. Finally, it is desirable to provide a mechanical ventilator user interface that allows the clinician to define the name of the newly created and saved respiratory therapy trajectory.